Method and apparatus for communicating with one of plural devices associated with a single telephone number

ABSTRACT

A system for (and a method of) selectively establishing communication with one of plural devices associated with a single telephone number is provided. In a preferred embodiment, the system includes a wireless connect unit connected between an enterprise private branch exchange (PBX) network and a public switched telephone network. The wireless connect unit preferably serves as a gateway between the PBX and one or more remote communication devices. The remote devices can be used as standard PBX office telephones for both inbound and outbound telephone calls. Thus, features of the PBX network (e.g., voice mail, direct extension dialing, corporate calling plan, etc.) are available to the remote device even though they are not physically connected to the PBX. When the system receives an incoming call, it can route the call to an office telephone and one or more of the remote devices simultaneously or as desired by the user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/593,543,filed Jun. 14, 2000 now U.S. Pat. No. 7,305,079, which claims priorityfrom provisional application Ser. Nos. 60/139,498, filed Jun. 14, 1999,and 60/185,070 filed Feb. 25, 2000, which are hereby incorporated byreference in their entireties.

BACKGROUND

It has become relatively common for individuals to possess a number ofdifferent devices through which they communicate. For example, a personmay have a home telephone, a wireless telephone, a pager and an officetelephone. As the population becomes increasingly mobile, making contactwith a person through one of these communication devices has become moredifficult.

Call forwarding is one method of addressing this problem. Certaintelephone systems allow users to enter another number to which a call isforwarded if not answered by a specified number of rings. This shouldallow an individual with multiple telephone devices to forward the callto such devices until the telephone at which the individual is locatedfinally rings. However, if several telephones are involved, thisapproach becomes complicated. Moreover, it requires the calling party toremain on the line for a significant period of time if the call is to beforwarded multiple times. Furthermore, it is necessary that callforwarding capabilities exist on each of the individual's telephones. Inaddition, this approach requires that all telephones involved bereprogrammed each time an individual desires to initiate callforwarding. A significant drawback to this forwarding strategy is that,in each leg of the forwarded call, the calling party is terminated onthe last device or network in the chain. It follows that the finalnumber in the forwarding scheme is responsible for all availableenhanced services or voice mail available to the caller. Accordingly,although a call may have been initially placed to an office telephoneequipped with voice mail and/or operator assist, all such enhancedservices of the corporate network are lost once the call is forwardedoff the corporate PBX (e.g., to the user's wireless telephone).

Travel can also exacerbate the difficulty of establishing communicationwith an individual having access to multiple telephone devices. Uponchecking into a hotel, the telephone in a traveler's hotel room becomesavailable as yet another potential means of contact. Unfortunately, thisforces a calling party to decide whether to attempt to contact thetraveler through his or her room telephone or other telephone device(e.g., wireless telephone or pager). If the traveler does not answer thecalled telephone, the calling party then must decide whether to leave amessage (unaware of when, or if, the message will be retrieved) orinstead attempt to reach the traveler via his or her other telephone.Likewise, if the traveler is expecting an important call but is unsurewhether it will be placed to his room telephone or wireless telephone,the traveler may feel compelled to remain within his room until the callhas been received. In addition, if the traveler's wireless telephonedoes not support certain types of long distance calls (e.g., to variousforeign countries), the traveler may be able to place certain types ofcalls only from his or her hotel room.

The office telephone is the primary point of contact of most businesspeople. Typically, corporations invest significantly in their officetelephone infrastructure, which often includes voice mail, paging andunified messaging systems. In addition, most corporations havenegotiated contracts with their telephone carriers (e.g., local and longdistance carriers) to ensure they obtain the lowest possible rates forcalls placed via their corporate network. However, because the corporateworkforce is becoming increasingly mobile, more business people areusing wireless telephones to conduct their business when they are out ofthe office. This has resulted in corporations spending a larger portionof their telecommunications budget on wireless communications, with farless favorable negotiated rates than the rates of their corporatenetwork. In addition, wireless communication systems often lack theenhanced conveniences (e.g., interoffice voice mail, direct extensiondialing, etc.) that corporate users have come to expect in the officeenvironment.

A solution to the aforementioned problems would be to allow wirelesstelephony devices (e.g., wireless telephones or pagers) to access anoffice telephone system as though they were desktop telephones connectedto the company's PBX. It is desirable to incorporate wireless devicesinto the PBX network so that users may place and receive telephone callsusing the office PBX telephone system even though they are at a remotelocation (e.g., out of the office). This would allow the enhancedconveniences of today's PBX networks (e.g., interoffice voice mail,direct extension dialing, etc.) to be available on wirelessdevices—something which is desperately needed in today's society.

There have been recent attempts to incorporate wireless telephones intoPBX networks. One system provided by Ericsson, requires the creation ofa mini-cellular network within the confines of the enterprise. Acellular switching unit, unique wireless telephones and an auxiliaryserver are required to route inbound telephone calls to a wirelesshandset serving as a remote office telephone.

An in-building wireless system has been proposed by Nortel Networks.This system requires the wiring of pico-cells throughout theenterprise's building. The system routes inbound telephone calls tospecialized wireless telephones serving as additional office PBXtelephones. The wireless telephones cannot be used as conventionalstandard wireless telephones until they leave the premises.

These systems allow inbound calls to be routed to an office telephoneand a wireless telephone, but they are not without their shortcomings.For example, each system requires specialized cellular equipment andwireless handsets. Moreover, the systems only use the wirelesstelephones for inbound telephone calls. In addition, these systemscannot use the wireless telephone as a conventional wireless telephone(i.e., not part of the enterprise's PBX network) within the building.

SUMMARY

A system for (and a method of) selectively establishing communicationwith one of plural devices associated with a single telephone number isprovided. In a preferred embodiment, the system includes a wirelessconnect unit connected between an enterprise private branch exchange(PBX) network and a public switched telephone network. The wirelessconnect unit preferably serves as a gateway between the PBX and one ormore remote communication devices. The remote devices can be used asstandard PBX office telephones for both inbound and outbound telephonecalls. Thus, features of the PBX network (e.g., voice mail, directextension dialing, corporate calling plan, etc.) are available to theremote device even though they are not physically connected to the PBX.When the system receives an incoming call, it can route the call to anoffice telephone and one or more of the remote devices simultaneously oras desired by the user.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary telecommunication system constructed inaccordance with an embodiment of the invention.

FIG. 2. illustrates a wireless connect unit in accordance with anembodiment of the invention.

FIG. 3 illustrates in flowchart form exemplary inboundstation-to-station call processing performed in accordance with anembodiment of the invention.

FIG. 4 illustrates in flowchart form exemplary inbound direct inwarddialing (DID) call processing performed in accordance with an embodimentof the invention.

FIG. 5 illustrates in flowchart form exemplary remote outbound callprocessing performed in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments and applications of the invention will now bedescribed. Other embodiments may be realized and structural or logicalchanges may be made to the disclosed embodiments without departing fromthe spirit or scope of the invention. Although the preferred embodimentsdisclosed herein have been particularly described as applied to abusiness or office environment, it should be readily apparent that theinvention may be embodied for any use or application having the same orsimilar problems.

The invention is more fully understood with reference to the preferredembodiments depicted in FIGS. 1-5. A first exemplary embodiment of theinvention is discussed and illustrated with reference to itsimplementation within an office building or other enterpriseestablishment. In an office, for example, personnel are assigned tooffices (or cubicles) with each office having an associated telephone.The office telephones are typically connected to a PBX, exchange, orother call processing infrastructure. The PBX allows each officetelephone to have its own telephone extension and a direct inward dial(DID) telephone number. As known in the art, a telephone extension istypically a three or four digit telephone number wherestation-to-station (i.e., office-to-office) calls can be placed bydialing the three or four digit extension. This is commonly referred toas direct extension dialing. As also known in the art, a DID telephonenumber allows external calls (i.e., calls initiated outside of theoffice PBX) to be placed directly to the office telephone.

The invention is not to be limited to any particular environment. Theinvention may be implemented, for example, in a hotel, boarding house,dormitory, apartment, or other commercial or residential establishment,where individuals are assigned to a unique extension or DID telephonenumber. The term “office” as used herein encompasses a singular room orspace within a business or other enterprise, or a hotel room or similarfacility. The term “user” as used herein encompasses office personnel,hotel guests or other individuals associated with a telephone extensionand DID telephone number.

FIG. 1 illustrates an exemplary telecommunication system 10 constructedin accordance with an embodiment of the invention. As will be discussedbelow, the system 10 provides for a full integration of remote telephonydevices, such as a wireless telephone 70, into an office or hotel PBX orother communications network. In doing so, the system 10 can selectivelyestablish communications with one of a plurality of telephony devicesassociated with a particular telephone extension or DID telephonenumber. Moreover, the system 10 will allow remote devices such as thewireless telephone 70 to perform as a fully functional standard officetelephone 12 a, 12 b for both inbound and outbound communications. Thatis, a remote device will be able to use features of the office network(e.g., direct extension dialing, corporate dialing plan, etc.) eventhough the device is not within the confines of the office or notdirectly connected to the office PBX. The system also allows thewireless telephone 70 to operate as an independent wireless telephone ifso desired. That is, the wireless telephone 70 may receive calls placedto its (non-office) DID telephone number even though the system 10routes PBX calls to the telephone 70.

The system 10 as particularly illustrated herein includes a conventionaloffice PBX network 11. The PBX network 11 may include a plurality ofstandard telephones 12 a, 12 b respectively connected to a conventionalPBX 14 via communication lines 18 a, 18 b. The PBX 14, which may be anycommercially available one such as a Meridian 1 PBX produced by NortelNetworks, is connected to a calling network such as a public switchedtelephone network (PSTN) 16 by a primary rate interface (PRI) connection20 or other suitable communication line or medium. The standardtelephones 12 a, 12 b can be any digital or analog telephone or othercommunication device known in the art. As illustrated in FIG. 1, thefirst telephone 12 a is a digital telephone while the second telephone12 b is an analog telephone. For clarity purposes only, two telephones12 a, 12 b are illustrated in FIG. 1, but it should be appreciated thatany number or combination of telephones or other communication devicescan be supported by the system 10. Moreover, although it is desirable touse digital telephones, the invention is not to be limited to theparticular type of telephone used in the system 10.

The PBX 14 is coupled to a wireless connect unit (WC) 30. The WC 30 isconnected to the PBX 14 in this embodiment by a PRI connection 22 orother suitable communication medium. The WC 30 is also connected to aPSTN 54 by a PRI connection or other suitable digital communicationmedium. The illustrated PRI connection between the WC 30 and the PSTN 54includes a first PRI connection 32, a channel service unit (CSU) 34, anda second PRI connection 36. As known in the art, a CSU is a mechanismfor connecting a computer (or other device) to a digital medium thatallows a customer to utilize their own equipment to retime andregenerate incoming signals. It should be appreciated that theillustrated connection between the WC 30 and the PSTN 54 is one of manysuitable connections. Accordingly, the invention should not be limitedto the illustrated connection. The WC 30 is one of the mechanisms thatallows the integration of remote devices (e.g., wireless telephone 70)into the PBX network 11 and its operation will be described below inmore detail.

The WC 30 is preferably connected to a local area network (LAN) 40 by anappropriate communication medium 38. Although a LAN 40 is illustrated,it should be appreciated that any other network could be used. Aplurality of computers (e.g., 42 a, 42 b) may be respectively connectedto the LAN 40 by any appropriate communication lines 44 a, 44 b. Thecomputers 42 a, 42 b can be used by network administrators or others tomaintain WC 30 and other portions of the system 10. The LAN 40 may alsobe connected to the Internet 50 by a suitable communication medium 48. Afirewall 46 may be used for security purposes. In a preferredembodiment, Internet 50 can be used to allow a remote administrationdevice 52 (e.g., a personal computer) to perform remote administrationof WC 30 by office personnel or other authorized users of the system 10.Remote administration will allow office personnel to set userpreferences for particular telephone extensions. Thus, each officetelephone extension and associated remote device is individuallyconfigurable.

PSTN 54 is connected in this embodiment to a commercial wireless carrier(or other carrier not co-located with the system 10) by a wirelessswitch 58 or other wireless carrier equipment by an appropriatecommunication medium 56. The wireless switch 58 is connected to at leastone antenna 60 (by an appropriate communication medium 62) fortransmitting signals 64 to a wireless device, such as the wirelesstelephone 70. The wireless device could also be a pager, personaldigital assistant (PDA), landline telephone, facsimile machine or otherwired/wireless communication device. It may desirable for the wirelessdevice to be capable of handling both (or either) digital and analogcommunication signals. It should be noted that any type of wirelesscommunication protocol (or a combination of different protocols), suchas TDMA, CDMA, GSM, AMPS, MSR, iDEN, WAP, etc., could be used.

It should be appreciated that the WC 30 is connected to a wirelesscarrier through a PSTN 54 and not by unique hardware or an in-officecellular network. As a result, WC 30 only has to interface withconventional components, such as the PBX 14 and PSTN 54. Thus, thesystem is substantially technology independent. Moreover, specialwireless devices are not required, which allows the remote device tofunction in its conventional manner (e.g., as a separate wirelesstelephone) and as part of the PBX network 11 (if so desired).

The WC 30 and the PBX 14 may also be connected to an accounting/billingsystem 80. The billing system 80 may also be connected to the LAN 40 sothat system administrators may access the contents of the billing system80. By incorporating a billing system 80 into the system 10, it ispossible to obtain immediate billing information for calls placedto/from the wireless telephone 70 or other remote device. This immediatebilling feature is not present in other PBX or enterprise networks andis particularly useful for corporate environments such as law firms andgovernment agencies, and hotel environments, where up to date billinginformation is essential.

As noted above, the WC 30 allows for the full integration of remotedevices into the PBX network 11. In a preferred embodiment, WC 30 is aprocessor-based stand-alone unit capable of handling communicationsdirected to the PBX network 11. In a preferred embodiment, WC 30 iscomposed of one or more processors generically represented by processormodule 310 executing one or more computer programs stored in one or morememory units generically represented by memory module 320, which iscoupled to processor module 310 via bus 330, as shown in FIG. 2. Memorymodule 320 also contains one or more databases and other processingmemory used during the overall operation of system 10, as will bedescribed below. Receiving and transmitting modules 340, 350,respectively, which are coupled to processor module 310 and memorymodule 320 via bus 330, are employed to receive and transmit informationto the PBX and PSTN during call processing, as well as receiving andtransmitting other information such as administrative information.

The modules (310, 320, 330, 340, 350) making up WC 30 may be implementedusing any known hardware or software devices. For example, in oneembodiment, workload performed by receiving and transmitting modules340, 350, as well as some of the processing functions of processormodule 310 of WC 30 are implemented using one or more conventionalprocessor-based programmable telephony interface circuit cards used tointerface WC 30 with PBX 14 and the PSTN. They are programmed to performthe conventional telephony services required to place and receive calls,as well as programmed to perform the unique call processing functionsdescribed below. The WC 30 preferably contain a database of officeextension numbers (also referred to herein as PBX extensions) and DIDtelephone numbers associated with each existing PBX extension. Thedatabase will be stored on a computer readable storage medium, which maybe part of (e.g., in memory module 320) or connected to the WC 30. Thedatabase may also contain a wireless connect/PBX extension (hereinafterreferred to as a “WC-PBX extension”) and one or more remote devicetelephone numbers associated with each PBX extension. In thisembodiment, software running on the telephony cards interfaces with thedatabase to perform the various call processing functions discussedbelow.

In this embodiment, the PBX 14 contains a coordinated dialing plan (CDP)steering table. The CDP steering table will be stored and retrieved froma computer readable storage medium, which may be part of or connected tothe PBX 14. The CDP steering table directs the routing of some or allPBX extensions to the WC 30 over the PRI 22 between the WC 30 and thePBX 14. In addition, the CDP steering table of the PBX 14 directs therouting of all WC-PBX extensions received from the WC 30 to theappropriate office telephone.

In accordance with a preferred embodiment of the invention, processormodule 310 executes one or more programs stored in memory module 320 toprocess calls received through PBX 14 or PSTN. FIGS. 3, 4 and 5illustrate some of the basic call processing events which WC 30 may beprogrammed to handle in accordance with exemplary embodiments of theinvention. As illustrated in FIG. 3, when an incoming station-to-stationcall (i.e., a direct extension call from one internal telephone deviceto another internal device) is received by the PBX 14 for an existingPBX extension (step 102), the PBX 14 looks up the PBX extension in theCDP steering table (step 104) to determine where the call should berouted. Based on the CDP steering table the call to the PBX extension isrouted to the WC 30 instead of directly to an office telephone 12 a(step 106).

As is known in the art, the incoming call will have automatic numberidentification (ANI) and dialed number identification service (DNIS)information. The ANI identifies the telephone number of the callingparty and is traditionally used for “caller ID.” DNIS identifies thetelephone number of the called party. The WC 30 reads the ANI/DNISinformation from the incoming call to obtain the DNIS information (step108). As noted above, the WC 30 has assigned a new WC-PBX extension toeach existing PBX extension. The WC-PBX extension, routing information,and user preferences are obtained by using the DNIS information(identifying the PBX extension) as an index into the WC 30 database(step 110). Routing information will include any additional remotetelephone numbers or voice mail box numbers, or other identificationnumbers of communication devices associated with the PBX extension.

At step 112, the WC 30 out pulses the PBX 14 through the PRI connection22 between the WC 30 and PBX 14 with the WC-PBX extension obtained instep 110. This causes the PBX 14 to ring the associated office telephone(e.g., telephone 12 a). At the same time (if desired), the WC 30attempts to contact one or more alternative communication devices (e.g.,by out dialing a remote telephone number via the PRI connection betweenthe WC 30 and the PSTN 54). In such embodiment, the station-to-stationcall is thus routed to both the office telephone and also to at leastone remote device 70 simultaneously or substantially simultaneously (oras determined by the user preferences). It should be noted that theillustrated processing 100 is one example of how an incomingstation-to-station call may be handled. Individual user preferences mayalter the way the call is processed. It should be noted that in apreferred embodiment, the WC 30 is dialing the remote device telephonenumber and out pulsing the PBX 14 with the WC-PBX extension. This givesthe WC 30 control over the connections to the office telephone 12 a andthe remote device 70. It should also be noted that the WC 30 can outdial several remote numbers, if so desired, and that the inventionshould not be limited to the dialing of one remote number.

At step 114, it is determined if the current ring count (i.e., number ofrings) exceeds the maximum ring count defined by the user. Since the WC30 is controlling the call at this time it can track the number ofrings. If the ring count exceeds the maximum ring count, then the WC 30(if desired) forwards the call to the enterprise's voice mail (step120). If the ring count does not exceed the maximum ring count, the WC30 determines if the call is answered at the PBX extension (step 116).The PBX 14 will issue an off-hook message to the WC 30 if theappropriate office telephone is answered. If it is determined that thecall is answered at the PBX extension, the WC 30 drops the call's pathto the remote device via the PSTN 54 and maintains the path to the PBX14 (step 122).

In a preferred embodiment, it may be desired that the call to the remotedevice is actually answered by the user and not by a service of thewireless carrier. In known systems, wireless carriers often answer acall if there is a bad connection, the wireless channels are overloadedor for other reasons (such as initiating a wireless carrier's answeringservice). When the wireless carrier answers the call in thesesituations, the call would appear to WC 30 as an “answered call” even ifthe remote user did not answer the call itself.

One way to distinguish a user answered call from a wireless serviceanswered call is to prompt the user to transmit an acknowledgementsignal such as a dual tone multi-frequency (DTMF) tone to the WC 30 viathe keypad of the remote device. Upon detecting the answered call, WC 30can send a voice message instructing the user to “press 1 to completethe call or press 2 to send caller to voice mail.” If the DTMF tone isnot received, then the WC 30 presumes that the call was answered by thewireless carrier, or that the user does not want to answer the callwhich the WC 30 treats as an unanswered call. If at step 118, it isdetermined that the remote device was answered by the user, the WC 30drops the WC-PBX extension path to the PBX and initiates the connectionbetween the calling party and the remote device (step 124). If the callis not answered at the remote device in step 118, process flow returnsto step 114 to check whether the ring count has exceeded the maximumring count. It should be noted that, if desired, the WC 30 can forwardan unanswered call to voice mail or play an interactive menu to thecalling party, which allows the calling party to page the called party,leave a voice mail message or to transfer to an operator.

In accordance with a preferred embodiment of the invention, the databaseof WC 30 may also contain numerous system-defined user access rights anduser modifiable preferences, which can alter the call processing of theinvention. An office administrator may use the network computers 42 a,42 b or a remote administration device 52 to set user access rights andpriorities (example discussed below with respect to outbound callprocessing 300 illustrated in FIG. 5). The user may use the remoteadministration device 52 to set numerous user preferences. It isdesirable that a Web-based or graphical user interface be used so thatthe user can easily access and set user preferences. The networkcomputers 42 a, 42 b (or remote device 52) may also be used by the userif so desired.

User preferences may include how the user associated with a particularPBX extension wants incoming calls to be routed. For example, the usercan request that incoming calls be routed to the office telephone andone or more remote devices simultaneously. The user instead can requestthat an incoming call be routed to the office telephone first, thenafter a user-defined number of rings, the remote device and eventuallysent to the PBX voice mail. Alternatively, the user can request that anincoming call be routed to the remote device first, then the officetelephone, and subsequently to the PBX voice mail. The user can requestthat all incoming calls be routed directly to the PBX voice mail. Theuser can request that a menu of options be played to the caller so thatthe caller can decide how to complete the call. The user can setseparate ring counts for the office telephone and remote device. Theuser can set dial tone options, which allows the user to control howlong a dial tone is played before a dial tone time-out occurs. The usercan adjust the time between dials. These are just a few of the userpreferences that can be stored and used by the WC 30, which can alterincoming and out going call processing. If the user does not change theuser preferences, or only changes a few preferences, system defaults areused.

When receiving an inbound DID call, call processing flow 200 (asillustrated in FIG. 4) is performed in accordance with an embodiment ofthe invention. At step 202, a DID telephone call is dialed by anexternal telephone device and received by system 10 through the PSTN. Ina preferred embodiment, PSTN has been programmed in advance to route allDID telephone numbers used by the system 10 to the WC 30. In addition,the PSTN has also been programmed to route calls incoming to the DIDtelephone number directly to the PBX 14 if the path to the WC 30 hasfailed. That is, the embodiment incorporates a failure path into thesystem 10 to ensure that a failure of the WC 30 or the PRI connectionbetween the WC 30 and the PSTN does not interrupt the operation of theoffice PBX network 11. This is possible since the steering table of theoffice PBX 14 contains the DID telephone numbers. The PBX 14 has thecapability to resolve these DID numbers. Thus, the PBX 14 can be used ifneeded to handle DID telephone calls. For purposes of this discussion,it is presumed that the WC 30 and the connection between the WC 30 andthe PSTN 54 are fully operational. Thus, at step 204, the PSTN routesthe DID call to the WC 30.

The WC 30 reads the ANI/DNIS information from the incoming DID call toobtain the DNIS information (step 206). The WC 30 resolves the call bydetermining what WC-PBX extension is associated with the telephonenumber identified by the DNIS. The WC-PBX extension, routing informationand user preferences are obtained by the WC 30 (step 208). At step 210,the WC 30 out pulses the PBX 14 through the PRI connection 22 betweenthe WC 30 and PBX 14 with the obtained WC-PBX extension. This causes thePBX 14 to ring the associated office telephone (e.g., telephone 12 a).At the same time (if desired), the WC 30 out dials one or more userdesignated remote telephone numbers via the PRI connections between theWC 30 and the PSTN 54. Therefore, the inbound DID telephone call isrouted to the office telephone and remote device simultaneously (or asdetermined by the user preferences). It should be noted that theillustrated processing 200 is just one example of how an incoming DIDcall may be handled.

At step 212, it is determined whether the current ring count exceeds themaximum ring count defined by the user. If the ring count exceeds themaximum ring count, then the WC 30 forwards the call to the enterprise'svoice mail (step 218). If the ring count does not exceed the maximumring count, the WC 30 determines whether the call is answered at the PBXextension (step 214). If it is determined that the call is answered atthe PBX extension, the WC 30 drops the call's path to the remotedevice(s) via the PSTN 54 and maintains the path to the PBX 14 (step220). If at step 214 it is determined that the call is not answered atthe PBX extension, the WC 30 determines if the call is answered at theremote device (step 216). In a preferred embodiment, it may be desiredthat the call to the remote device is actually answered by the user andnot by a service of the wireless carrier. Therefore, to distinguish auser answered call from a wireless service answered call, the WC 30 mayprompt the user to transmit a DTMF tone to the WC 30 via the remotedevice when the user answers the call. If the DTMF tone is not received,then the WC 30 preferably presumes that the call was answered by thewireless carrier, which is interpreted by the WC 30 as an unansweredcall. If at step 216 it is determined that the remote device wasanswered by the user, the WC 30 drops the path to the PBX 14 andmaintains the connection to the remote device (step 222). (As analternative, control and responsibility for the remainder of the callcan be left with the PSTN in order to free up PRI channels between WC 30and PSTN 54.) If the call is not answered at the remote device in step216, process returns to step 212 to check whether the ring count hasexceeded the maximum ring count.

Initially, the call processing reduces the processing load on the PBX14, since the WC 30 (and not PBX 14) is resolving the DID telephonenumbers. This allows the PBX 14 to handle call processing for moreextensions if desired. Additionally, since the WC 30 is resolving theDID calls, the WC 30 can out pulse the PBX 14 and out dial the PSTN 54simultaneously (if desired) without waiting for the PBX 14 toprocess/resolve the call. Moreover, as noted above, redundancy isprovided by allowing the PBX network 11 to function as a standard PBX ifthe WC 30 or the link between the WC 30 and the PSTN 54 fails.

In accordance with a preferred embodiment, WC 30 allows a remote devicesuch as a wireless telephone 70 to act as an office PBX telephone foroutbound telephone calls following call processing flow 300 illustratedin FIG. 5. That is, a user will be able to use its wireless telephone(or any remote device) to make station-to-station calls as if he wereusing an office telephone directly connected to the office PBX 14. Fromthe remote device, the user will also be able to perform other PBXfunctions as well. At step 302, a user places a call to the WC 30 fromthe remote device. One way for the user to do this would be to define aspeed dial key (or sequence of keys) on the wireless telephone handset.When the user activates the appropriate speed dial key/keys, thewireless telephone dials into the WC 30. Another way dial into the WC 30would be by fixed dialing. Fixed dialing is a feature provided by thewireless carrier to always connect the wireless telephone to aparticular number or service, and, in this case, it would connect theuser to the WC 30. Any number of other methods may be used to dial intothe WC 30.

At step 304, the WC 30 reads the ANI/DNIS information received from theremote device to obtain the ANI information. The ANI identifies thetelephone number of the wireless telephone. The WC 30 uses the ANIinformation to obtain the wireless user's access rights and userpreferences (step 306). As noted above, a user is provided with theability to set various user preferences. The enterprise itself has theability to set access rights defining what type of calls the user canplace from the remote device (e.g., local, long distance, international,station-to-station, etc.). For example, if using PRI connections betweenthe PSTN 54 and the WC 30, the PBX 14 and the WC 30, and the PBX 14 andthe PSTN 16, users can be assigned into particular access groups byassigning each user to a particular channel or group of channels of thePRI. The user assignments can be stored in a database memory withinmemory module 320 of WC 30 for access during a validation orauthentication process performed by processor module 310. In thealternative, the responsibility over the user assignments can beincorporated into PBX 14 or some other (on-site/remote) equipment.

As is known in the art, in North America and Japan, for example, eachPRI contains 23 “B” channels that can be used for voice communications.Each B channel can be programmed with different calling capabilities bythe PBX 14. That is, some channels can be programmed for all types ofcalls (e.g., international, long distance, local etc.), others for longdistance and local calls, while others can be programmed solely forlocal or internal station-to-station calls. The channels can also berestricted to a limited number of authorized telephone numbers as well.The programming can be determined by the enterprise. Since the channelscan be programmed with different calling capabilities, the enterprisecan implement different access groups, with each group defining a user'sremote device access.

This feature significantly limits the enterprise's remote device (e.g.,wireless service) costs because user access to services can besubstantially restricted. For example, the enterprise may want deliverypersonnel to have a wireless telephone for internal dialing purposes,but may be afraid of misuse by the personnel. Implementing the aboveembodiment, the enterprise can group all wireless telephones assigned toits delivery personnel to a channel(s) restricted solely to internalcalls. Any grouping is possible. Priorities may also be assigned. A userassigned to group 1 (programmed for all calling capabilities) may begiven priority to bump a user assigned to group 2 (having less callingcapabilities) in the event that the channels assigned to group 1 arebusy. Any grouping or priority scheme can be implemented by theenterprise and is application specific.

At step 308, the WC 30 “spoofs” a dial tone to the wireless telephone.That is, the WC 30 generates and transmits a dial tone to the wirelesstelephone 70 as if the user had picked up an office telephone 12 aconnected to the PBX 14. In a preferred embodiment, the spoofing of thedial tone is achieved by the WC internally generating the appropriatetone (e.g., through software or hardware modules). The dial tone is thenplayed to a wireless telephone as a prompt while waiting to receive DTMFdigits from the wireless user indicating the telephone number the userwishes to dial. At this point in the call process flow 300, the user isconnected to the office PBX and may access any of its standard features.For purposes of this illustrated embodiment, it is presumed that theuser wishes to place an outbound call at this time. At step 310, theuser attempts to place a call and the WC 30 receives the number dialedby the user. At step 312, the WC 30 determines if the user is authorizedto make the call. For example, the WC 30 checks the user's accessrights, and if the user is authorized to place the call, the call isrouted to the correct channel by the WC 30 based on user preferences,access rights and the channel definitions (step 314). If the user is notauthorized to place the call (i.e., the call exceeds the user's accessrights), the WC 30 performs unauthorized call processing (step 316).Unauthorized call processing may include playing a message to the userstating that the user does not have authority to place the call,disconnecting the call, or any other action desired by the enterprise.

If the user decides to place a station-to-station call, for example, thecall would appear to be an internally dialed call at the destinationoffice telephone. For example, if the PBX 14 uses a different ring forinternal calls, then the internal ring would be sent to the officetelephone even though the call was made by the wireless telephone. Ifthe PBX 14 normally displays the PBX extension of the calling party onthe called office phone, then the PBX extension of the calling partywould be displayed on the called office telephone even though the callwas initiated by the wireless telephone.

Many enterprises have already provided wireless communications devicesto their personnel. These wireless devices already have existingtelephone numbers and are external to the enterprise PBX. Since thedevices are already in use by personnel and their clients, theenterprise does not want to change their telephone numbers. There is aneed to integrate these telephone numbers into the enterprise PBX. Oneway to integrate these telephone numbers would be to forward theirunanswered calls to the PBX voice mail. This can be accomplished by theinvention whether the wireless telephone number is associated with a PBXextension or not.

For example, the enterprise can purchase additional DID telephonenumbers from the telephone company (if necessary). These additional DIDtelephone numbers are stored in the database of the WC 30 together withspecial routing instructions to route all calls directly to a user's PBXvoice mail box (or other destination as desired). The user of a wirelesstelephone can program the wireless telephone to forward unanswered callsto his associated DID telephone number. Alternatively, the user can havethe wireless carrier forward unanswered calls to the DID telephonenumber as well. This way, any unanswered call to the wireless telephonewill be forwarded to the WC 30, which resolves the DID and forwards thecall to the appropriate PBX voice mail box. Using this feature, thelikelihood is increased that the user will retrieve his messages sincehe can retrieve all of his messages through the PBX voice mail. Thisalso alleviates the need for the user to have a separate voice mailservice from the wireless carrier, which may reduce the cost of thewireless service.

The invention can be embodied in any number of different applications.One embodiment, for example, applies the invention to a hotel having alarge number of rooms with dedicated phones lines for each room toprovide a second or “virtual phone line” without routing additionaltelephone lines or other wiring to the room. Each room would have theoriginal hard-wired telephone extension that is connected to theenterprise PBX, as well as a wireless telephone associated with the PBXextension (integrated using the invention) serving as a second orvirtual telephone line. If, for example, a guest of the hotel were usingthe hard-wired telephone line for his personal computer, he could stillmake and receive calls through the PBX with the wireless telephone.Thus, the invention allows an enterprise to double its telephone lineswithout incurring the expense of additional wiring required to install asecond line for the hotel rooms.

Another exemplary embodiment involves application of the invention tofacilitate communications in enterprises that have large offices locatedin different parts of the country. Typically, these enterprises utilizeseparate PBX networks for each location. The separate PBX networks areoften connected together using tie-lines, so that one location can makea station-to-station call to the other location. That means person A atlocation A can contact person B at location B using the PBX networks.The call will be a long distance call, but the enterprise usuallynegotiates a discount rate with the telephone carrier for dedicated, lowrate long distance service. However, if person B is not in his office,person A will have to use other means to contact person B. Thistypically involves a call to person B's wireless telephone, which wouldbe an expensive long distance wireless telephone call. In thisembodiment, using a WC unit in location B, the office and wirelesstelephones associated with person B would ring simultaneously. If personB answers the wireless telephone, the enterprise will not incur anexpensive long distance wireless telephone charge. Instead, since the WCunit at location B is initiating the wireless telephone call, thewireless call will only be a relatively inexpensive local call to thepertinent wireless carrier. Moreover, if the enterprise can contractwith the wireless carrier to get unlimited local wireless telephonecalls, the charge to the enterprise would be even less. Where a WC unitis installed in both locations A and B, person A can also place the callfrom a wireless telephone (through the WC unit at location A) to personB, who can answer the call with a wireless telephone (through the WCunit at location B). That is person A and person B can communicatethrough their respective PBX networks even though person A and person Bare away from their offices when the call is placed.

In a preferred embodiment, WC 30 is co-located with the enterprises' PBX14, but may also be centrally located in a remote location ordistributed among the many locations, or any combination of thesearrangements.

While preferred embodiments have been specifically described andillustrated herein, it should be apparent that many modifications to theembodiments and implementations of the invention can be made withoutdeparting from the spirit or scope of the invention. For example, whilethe preferred embodiments illustrated herein have been limited to theprocessing of voice (packet or circuit switched) calls, it should bereadily apparent that any form of call (e.g., audio, video, data) may beprocessed through WC 30 to any communication device (e.g., cellularphone, pager, office/residential landline telephone, computer terminal,personal digital assistant (PDA), etc.). The individual method steps ofthe exemplary operational flows illustrated in FIGS. 2-4 may beinterchanged in order, combined, replaced or even added to withoutdeparting from the scope of the invention. Any number of differentoperations not illustrated herein may be performed utilizing theinvention.

In addition, while the illustrated embodiments have demonstratedimplementations of the invention using PBX-based communication systems,it should be readily apparent that the WC module may be connected(directly, indirectly, co-located, or remotely) with any other networkswitching device or communication system used to process calls such as acentral switching office, centrex system, or Internet server fortelephone calls made over the public switched telephone network, privatetelephone networks, or even Internet Protocol (IP) telephony networksmade over the Internet.

It should be apparent that, while only PRI lines (e.g., between PBX 14and WC 30, between PBX 14 and PSTN 16) have been illustrated indiscussing preferred embodiments of the invention, these communicationlines (as well as any other communication lines or media discussedherein) may be of any form, format, or medium (e.g., PRI, T1, OC3,electrical, optical, wired, wireless, digital, analog, etc.). Moreover,although PSTN 16, 54 are depicted as separate networks for illustrationpurposes, it should be readily apparent that a single PSTN network alonemay be used in reducing the invention to practice. It should be notedthat the WC 30 could trunk back to the PBX 14 instead of being directlyconnected to the PSTN 54. The use of a commercial wireless carriernetwork (represented by wireless switch 58 and antenna 60) as describedherein may be implemented using one or more commercial carriers usingthe same or different signaling protocols (e.g., Sprint PCS and Nextel,etc.) depending on the communication devices registered with the system.

The modules described herein such as the modules making up WC 30, aswell as WC 30 and PBX 14 themselves, may be one or more hardware,software, or hybrid components residing in (or distributed among) one ormore local or remote systems. It should be readily apparent that themodules may be combined (e.g., WC 30 and PBX 14) or further separatedinto a variety of different components, sharing different resources(including processing units, memory, clock devices, software routines,etc.) as required for the particular implementation of the embodimentsdisclosed herein. Indeed, even a single general purpose computerexecuting a computer program stored on a recording medium to produce thefunctionality and any other memory devices referred to herein may beutilized to implement the illustrated embodiments. User interfacedevices utilized by in or in conjunction with WC 30 may be any deviceused to input and/or output information. The interface devices may beimplemented as a graphical user interface (GUI) containing a display orthe like, or may be a link to other user input/output devices known inthe art.

Furthermore, memory units employed by the system may be one or more ofthe known storage devices (e.g., Random Access Memory (RAM), Read OnlyMemory (ROM), hard disk drive (HDD), floppy drive, zip drive, compactdisk-ROM, DVD, bubble memory, etc.), and may also be one or more memorydevices embedded within a CPU, or shared with one or more of the othercomponents. Accordingly, the invention is not to be seen as limited bythe foregoing description, but is only limited by the scope of theappended claims.

1. A telecommunication device comprising: a receiving module forreceiving an incoming call from a calling device; and a programmedprocessor connected to the receiving module for: identifying a telephonenumber associated with a recipient of the incoming call, using theidentified telephone number to form a first communication path betweensaid processor and a first communication device by dialing a firsttelephone number and a second different communication path between saidprocessor and a second communication device by dialing a secondtelephone number, holding the incoming call for a predetermined timeuntil it is determined that the call to the telephone number associatedwith the recipient has been answered at the first or secondcommunication device, authenticating the answering one of the first andsecond communication devices by requesting an acknowledgement signalbefore forming a completed physical circuit connection between thecalling device and the device the recipient has answered; and routingthe incoming call to the answered device using the completed physicalcircuit connection; wherein said processor is further programmed toprompt a caller of the incoming call with a menu of call destinationoptions for the recipient of the incoming call and said processor formsat least one of said first communication path and said secondcommunication path in accordance with an option selected by the caller.2. The device of claim 1, wherein said processor routes the incomingcall to a voice mailbox telephone number after the predetermined timeexpires.
 3. The device of claim 2, wherein said predetermined timecorresponds to a number of telephone rings.
 4. The device of claim 1,wherein the incoming call is routed to a retrieved telephone numberassociated with a cellular telephone.
 5. The device of claim 1, whereinthe answered device can operate independently from the telecommunicationdevice.
 6. A method of routing a communication from a calling device toa called party associated with a dialed telephone number, the methodcomprising the steps of: receiving at a processor the communication madeto the dialed telephone number; holding the received communication inthe processor; identifying a telephone extension using informationwithin the received communication; using the identified extension toretrieve a first communication device number associated with the calledparty and a second communication device number associated with thecalled party; forming a first communication path between the processorand a first communication device associated with the first communicationdevice number by placing a first call to the first communication devicenumber; forming a second communication path between the processor and asecond communication device associated with the second communicationdevice number by placing a second call to the second communicationdevice number; determining if the first communication device answeredthe first call, and if the first call is answered, authenticating thefirst communication device by requesting an acknowledgement signal fromthe first communication device and routing the held receivedcommunication to the first communication device to form a completedphysical circuit connection between the calling device and the firstcommunication device after the acknowledgement signal has been received;determining if the second communication device answered the second call,and if the second call is answered, authenticating the secondcommunication device by requesting an acknowledgement signal from thesecond communication device and routing the held received communicationto the second communication device to form a completed physical circuitconnection between the calling device and the second communicationdevice after the acknowledgement signal has been received; and promptinga caller of the incoming call with a menu of call destination optionsfor the recipient of the incoming call and forming at least one of saidfirst communication path and said second communication path inaccordance with an option selected by the caller.
 7. The method of claim6, further comprising the step of routing the received communication toa voice mailbox number after a predetermined number of rings.
 8. Themethod of claim 6, further comprising the step of routing the receivedcommunication to a voice mailbox number after a predetermined timeexpires.
 9. The method of claim 6, wherein the first communicationdevice is a cellular telephone and the second communication device is alandline telephone.
 10. The method of claim 6, wherein the firstcommunication device is a personal digital assistant and the secondcommunication device is a landline telephone.
 11. A telecommunicationapparatus comprising: a processor programmed to: receive a communicationmade to a dialed telephone number; hold the received communication;identify a telephone extension using information within the receivedcommunication; use the identified extension to retrieve a firstcommunication device number associated with a called party and a secondcommunication device number associated with the called party; place afirst call to the first communication device number to form a firstcommunication path between the processor and a first communicationdevice associated with the first communication device number; place asecond call to the second communication device number to form a secondcommunication path between the processor and a second communicationdevice associated with the second communication device number; determineif the first communication device answered the first call, and if thefirst call is answered, authenticate the first communication device byrequesting an acknowledgement signal from the first communication deviceand route the held received communication to the first communicationdevice to form a completed physical circuit connection between thecalling device and the first communication device after theacknowledgement signal has been received; and determine if the secondcommunication device answered the second call, and if the second call isanswered, authenticate the second communication device by requesting anacknowledgement signal from second communication device and route theheld received communication to the second communication device to form acompleted physical circuit connection between the calling device and thesecond communication device after the acknowledgement signal has beenreceived; wherein said processor is further programmed to prompt acaller of the incoming call with a menu of call destination options forthe recipient of the incoming call and said processor forms at least oneof said first communication path and said second communication path inaccordance with an option selected by the caller.